Process of correcting printing plates



@cflz. 23, 1928. 1,688,647

E. E. NOVOTNY PROCESS OF CORRECTING PRINTING PLATES Original Filed Feb.9, 1926 We; 18 17 9 -r A M/[@ L I I f WNTOR.

4' v I n I W ;%RNEY.

Patented Oct. 23, 1928.

UNITED STATES PATENT oFncE;

EMIL E. NOVOTNY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO JOHN STOG-DELL STOKES, 0] SPRING VALLEY FARMS, HUNTINGTON VALLEY POST OFFICE,

PENNSYLVANIA.

PROCESS OF CORRECTING PRINTING PLATES.

Original application filed February 9, 1926, Serial No. 87,111. Dividedand this application filed November 18, 1926, Serial No. 149,452.Renewed April 20, 1928.

This invention relates to a process of correcting printing plates. Themethod is particularly directed to the correctin of a particular type ofprinting plate W ereln the printing plate comprises a speclal,nonhomogeneous sprayed metal having great thermoplasticity.

The present application is a division of my copending application SerialNo. 87,111, filed February 9, 1926, for printing plate and method ofmaking the same.

Briefly stated, my method is directed to the correction of metallicprinting plates formed through the action of a metallic spray in such amanner that a porous, non-homogeneous structure will be produced. Thisprinting plate body, because of its lack of homogeneous qualities iscapable of being rendered thermoplastic by being heated to a temperaturewell below its melting point and may, therefore, be compressedthroughout its entire area or within certain localized areas in orderthat the regularities or irregularities required of a printing plate-maybe compressed therein by any suitable means. Any equipment capable ofapplying the required uniform pressure to produce the regularities andirregularities, such as a suitable hydraulic press or other similarequipment, is suitable for my purpose. If the printing plate were ofsolid homogeneous metal, compression would produce more or less lateralflow which would tend to distort the body of the plate.

After long experimentation with eutectic alloys in the form of foil andplastic metal, I have discovered that an alloy such as foundary type,monotype, or similar metals including various alloys comprising metalssuch as lead, tin and antimony, is most useful for my purpose. Thesealloys when applied to a suitable original by means of a metallic sprayproperly adjusted form a structure which is not homogeneous, and theparticles are therefore combined in a structure having a smooth, clean,polished working face but a body'of more or less 0 en porous structure.The particles upon stri ing the surface of a properly prepared matrixdeposit thereon without reboundin therefrom and form small, thin,scaleli e portions, apparently having oxidized faces, the oxide orperhaps the cooling of the thin sections preventing the formation of asolid homogeneous welded body. Apparently, too, where alloys are used,certain of the lowest melting components, such as the eutectic alloys ofthe composition, are thrown out to the edges and these tend to hold thestructurein form, with the addition, however, of a certain intermeshingor commingling of the odd size par- 7 ticles of the spray. Be that as itmay, however, actual experimentation has proven that thesenon-homogeneous plates, whether made of an alloy or of a solid metal butso long as they are sprayed in an open non-homogeneous manner, willdisplay remarkable thermoplas1c propert es. This is very well covered inmy copendmg application previously reigrged to, Serial N 0. 87,111,filed February 9,

Even though the printing plate should have a relatively tough facingsection formed by depositing harder metals either by means of thesprayor by means of an electrolytic deposit, the body portion when made by myspray method will still retain its thermoplastic properties, andtherefore it is not essential that the printing plate be made entlrelyof non-homogeneous material as it may be a composite structure.

This composite structure may comprise a plate consisting of similarmaterials throughout but having a fine deposit on its face sect1onfollowed by a relatively coarse deposit for the backing or body section,or may consist of dissimilar materials such as, for example, theapplication of a harder and tougher material for the working face. Inother words, a printing plate comprising substantially a body portion ofsprayed metal havlng open, porous non-homogeneous characteristics isuseful for my purpose.

In the accompanying drawings Fig. 1 is a cross sectional View of aprinting plate made by my method wherein a fine face spray is firstapplied and which is subsequently backed with a coarser sprayed bodyforming section.

Fig. 2 is a cross sectional view of a modified form of printing platesimilar to that shown in Fig, 1 with the exception, however, that aharder face coating is applied either by means of a spray or by asubsequent electrolytic deposit.

' proximately/100 to 500 F. where monotype metal is used for theproduction of the printing plate. The printing plate face 18 ispreferably placed against the polished surface plate S and properpressure is applied by means of screw 22 .operating against the platen23. A suitable resilient blanket (not shown) is preferably placedbetween the back of the printing plate 20 and the lower section of thepressure platen 23 in order that a light pressure may be applied andthat any irregularities may be taken up in this blanket. A suitablecooling means is provided as by means of the inlet hole 24 and outlethole 25, for the admission of cooling water in order 7 that the platemay be quickly cooled by circulatin cooling water in a properly coredcooling plate.

While'I have herein shown and described certain preferred embodiments ofmy invention I wish it to be understood that I do not con ne myself toall of the precise details herein set forth, as modifications andvariations may be made without departing from the spirit of theinvention or exceeding the scope of the appended claims. I

What I claim is- 1. The herein described method of leveling a printingplate which consists in providing a printing plate comprising an open,porous sprayed metallic structure having great thermoplasticity whenheated below the melting point of the metal and placing said plate on asuitable support, and while thermoplastic applying pressure to cause theface of the printing plate to assume the desired regularities andirregularities and then allowing the printing plate to set by cooling.

2. The herein described method of leveling a printing plate whichconsists in providing a printing plate comprising an open, poroussprayed metallic structure having great thermoplasticity when heatedbelow the melting point of the metal and placing said plate on asuitable support, and while thermoplastic applying pressure to cause theface of the printing plate to assume the desired regularities andirregularities and then allowing the printing plate to set by cooling,and shaving the back thereof.

3. The herein described method of leveling a printing plate whichconsists in providing a printing plate comprising an open, poroussprayed metallic structure having great thermoplasticity when heatedbelow the melting point of the metal and placing said plate on asuitable support, and while thermoplastic applying pressure to cause theface of the printing plate to assume the desired regularities andirregularities and then allowing the printing plate to set by cooling,and leveling the back thereof.

Signed at Philadelphia in the county of

